Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <4f02d91a-acd8-afa5-03b0-fd8ec29328dd@redhat.com>
Date:   Tue, 18 Jul 2023 19:17:02 +0800
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.10.0
Subject: Re: [PATCH v6 09/11] KVM: arm64: Flush only the memslot after
 write-protect
Content-Language: en-US
To:     Raghavendra Rao Ananta <rananta@google.com>,
        Oliver Upton <oliver.upton@linux.dev>,
        Marc Zyngier <maz@kernel.org>,
        James Morse <james.morse@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>
Cc:     Paolo Bonzini <pbonzini@redhat.com>,
        Sean Christopherson <seanjc@google.com>,
        Huacai Chen <chenhuacai@kernel.org>,
        Zenghui Yu <yuzenghui@huawei.com>,
        Anup Patel <anup@brainfault.org>,
        Atish Patra <atishp@atishpatra.org>,
        Jing Zhang <jingzhangos@google.com>,
        Colton Lewis <coltonlewis@google.com>,
        David Matlack <dmatlack@google.com>,
        linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev,
        linux-mips@vger.kernel.org, kvm-riscv@lists.infradead.org,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org, Gavin Shan <gshan@redhat.com>
References: <20230715005405.3689586-1-rananta@google.com>
 <20230715005405.3689586-10-rananta@google.com>
From:   Shaoqin Huang <shahuang@redhat.com>
In-Reply-To: <20230715005405.3689586-10-rananta@google.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 7/15/23 08:54, Raghavendra Rao Ananta wrote:
> After write-protecting the region, currently KVM invalidates
> the entire TLB entries using kvm_flush_remote_tlbs(). Instead,
> scope the invalidation only to the targeted memslot. If
> supported, the architecture would use the range-based TLBI
> instructions to flush the memslot or else fallback to flushing
> all of the TLBs.
> 
> Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
> Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
> ---
>   arch/arm64/kvm/mmu.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> index 387f2215fde7..985f605e2abc 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -1082,7 +1082,7 @@ static void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot)
>   	write_lock(&kvm->mmu_lock);
>   	stage2_wp_range(&kvm->arch.mmu, start, end);
>   	write_unlock(&kvm->mmu_lock);
> -	kvm_flush_remote_tlbs(kvm);
> +	kvm_flush_remote_tlbs_memslot(kvm, memslot);
>   }
>   
>   /**

-- 
Shaoqin